PROBLEM TO BE SOLVED: To provide an apparatus that acquires correct internal functional information even if plural measurement positions are displaced from each other, in the apparatus to compare and calculate a plurality of measurement results to acquire internal functional information.SOLUTION: The functional information acquisition apparatus includes: an absorption coefficient acquisition part to acquire first data showing a profile of a first absorption coefficient corresponding to light of a first wavelength from signals corresponding to the light of the first wavelength, and second data showing a profile of a second absorption coefficient corresponding to light of a second wavelength different from the first wavelength from signals corresponding to the light of the second wavelength and having an image spatial resolution lower than that of the first data； and a functional information acquisition part to acquire functional information using the first data and the second data.SELECTED DRAWING: Figure 2
